1. Field of the Invention
The present invention relates to an electronic device, a method of extracting data, and a program.
2. Background Art
There is an electronic device that acquires data at every fixed sampling period that is set by a user, as one electronic device that periodically acquires the data, such as a running watch that measures and memorizes living-body information, or a car navigation system that determines current positioning and retains history of the positioning.
On the other hand, in Japanese Patent No. 03415971, a measurement device is disclosed that can retain data at a time interval that depends on data acquirement time. In the measurement device disclosed in Japanese Patent No. 03415971, a result of measurement such as the number of heartbeats is compressed into data with two or more different compression ratios with respect to time and the compressed data is stored in a compressed-data storage unit that corresponds to the compressed data, and a display control unit displays changes in the result of measurement over time on a display unit, based on the compressed data stored in a compressed-data storage unit that has the largest number of items of data.
Accordingly, in the measurement device disclosed in Japanese Patent No. 03415971, although the display device is not enlarged, the changes in the result of measurement over time can be properly displayed regardless of whether measurement time is long or short.
However, in the electronic device that acquires the data at every fixed sampling period, if data acquirement time is long, a memory capacity is exceeded in the process. Thus, the subsequent data cannot be retained or the data needs to be removed in chronological order in which the data is stored. Because of this, the user cannot grasp a trend of the data over the data acquirement time.
In contrast, because the data can be retained at the time interval that depends on the data acquirement time in the measurement device disclosed in Japanese Patent No. 03415971, the user can grasp the tendency of the data over the data acquirement time. However, in the measurement device disclosed in Japanese Patent No. 03415971, processing load is increased in that the result of measurement is compressed into the data with the two or more different compression ratios with respect to time. If the processing load can be reduced, the electronic device (the measurement device in Japanese Patent No. 03415971) can be made smaller in size, and a production cost or an operational cost can be reduced.